Airworthiness Directives; Hamilton Sundstrand Power Systems T-62T-46C12 Auxiliary Power Units

Summary:

The FAA is adopting a new airworthiness directive (AD) for Hamilton Sundstrand Power Systems T-62T-46C12 auxiliary power units (APUs). This AD requires upgrading the software in the APU full-authority digital controller (FADEC) from software version 02.01.000 to version 03.00.000. This AD results from two reports of APU compartment explosions due to over-fueling of the APU at low revolutions-per-minute during the start sequence. We are issuing this AD to prevent over-fueling of the APU during the start sequence, which could lead to fuel explosions, injury, and damage to the APU and the airplane.

Table of Contents

Addresses:

You can get the service information identified in this AD from Hamilton Sundstrand Technical Publications, One Hamilton Road, Mail Stop: 1A-3-Z63, Windsor Locks, CT 06096-1010; telephone (860) 654-3575.

The Docket Operations office is located at Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.

For further information contact:

Roger Pesuit, Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate, 3960 Paramount Blvd., Lakewood, CA 90712; e-mail:roger.pesuit@faa.gov; telephone (562) 627-5251, fax (562) 627-5210.

Supplementary information:

The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to Hamilton Sundstrand Power Systems T-62T-46C12 APUs. We published the proposed AD in the Federal Register on April 13, 2009 (74 FR 16811). That action proposed to require upgrading the software in the APU FADEC from software version 02.01.000 to version 03.00.000.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Comments

We provided the public the opportunity to participate in the development of this AD. We have considered the comment received.

One commenter states that we should reference Revision 2 of Hamilton Sundstrand Power Systems Service Bulletin (SB) No. 4503067-49-12 instead of referencing Revision 1 of that SB. Revision 1 had a technical error in it that prevented loading the software change.

We agree. We changed the AD to reference Revision 2 of the SB.

Conclusion

We have carefully reviewed the available data, including the comment received, and determined that air safety and the public interest require adopting the AD with the change described previously. We have determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

Costs of Compliance

We estimate that this AD will affect 59 Hamilton Sundstrand Power Systems T-62T-46C12 APUs installed on airplanes of U.S. registry. We also estimate that it will take about three work-hours per APU to perform the actions, and that the average labor rate is $80 per work-hour. There is no required part cost. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $14,160.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government.

For the reasons discussed above, I certify that this AD:

(1) Is not a “significant regulatory action” under Executive Order 12866;

(2) Is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

(3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary at the address listed under ADDRESSES.

List of subjects in 14 cfr part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends 14 CFR part 39 as follows:

Part 39—airworthiness directives

1. The authority citation for part 39 continues to read as follows:

Authority:

49 U.S.C. 106(g), 40113, 44701.

§ 39.13 2. The FAA amends § 39.13 by adding the following new airworthiness directive:

2009-21-03Hamilton Sundstrand Power Systems: Amendment 39-16040. Docket No. FAA-2009-0247; Directorate Identifier 2009-NE-07-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective November 20, 2009.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Hamilton Sundstrand Power Systems T-62T-46C12 auxiliary power units (APUs). These APUs are installed on, but not limited to, Bombardier Inc. DHC-8-400 series airplanes.

Unsafe Condition

(d) This AD results from two reports of APU compartment explosions due to over-fueling of the APU at low revolutions-per-minute during the start sequence. We are issuing this AD to prevent over-fueling of the APU during the start sequence, which could lead to fuel explosion, injury, and damage to the APU and the airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.

Software Upgrade of the APU Full-Authority Digital Electronic Controller (FADEC)

(f) At the next FADEC removal, but no later than 18 months after the effective date of this AD, upgrade the software in the APU FADEC from software version 02.01.000 to version 03.00.000, and change the FADEC part number (P/N) from 4503069E to 4503069F.

(g) Use paragraphs 3.A through 3.F.(2) of the Accomplishment Instructions of Hamilton Sundstrand Power Systems Service Bulletin No. 4503067-49-12, Revision 2, dated March 9, 2009, to do the software upgrade and the FADEC P/N change.

Alternative Methods of Compliance

(h) The Manager, Los Angeles Aircraft Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.

Related Information

(i) Contact Roger Pesuit, Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate, 3960 Paramount Blvd., Lakewood, CA 90712; e-mail:roger.pesuit@faa.gov; telephone (562) 627-5251, fax (562) 627-5210, for more information about this AD.

Material Incorporated by Reference

(j) You must use Hamilton Sundstrand Power Systems Service Bulletin No. 4503067-49-12, Revision 2, dated March 9, 2009, to perform the actions required by this AD. The Director of the Federal Register approved the incorporation by reference of this service bulletin in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Contact Hamilton Sundstrand Technical Publications, One Hamilton Road, Mail Stop: 1A-3-Z63, Windsor Locks, CT 06096-1010; telephone (860) 654-3575, for a copy of this service information. You may review copies at the FAA, New England Region, 12 New England Executive Park, Burlington, MA; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to:http://www.archives.gov/federal-register/cfr/ibr-locations.html.

Issued in Burlington, Massachusetts, on September 30, 2009. Peter A. White,

Assistant Manager, Engine and Propeller Directorate, Aircraft Certification Service.

References

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